Interlacing nozzle for the production of yarns with knots and method for interlacing yarns

ABSTRACT

The invention relates to an interlacing nozzle ( 100 ) for the production of knotted yarns, interlaced yarn, of DTY or plain yarns with knots. The interlacing nozzle ( 100 ) comprises a yarn channel ( 1 ) with an air twist chamber ( 2 ). The air twist chamber ( 2 ) includes an injection port ( 4 ) for introducing air into the air twist chamber ( 2 ). A channel axis (M) extends in a yarn guiding direction (F). The yarn channel ( 1 ) comprises a channel width ( 21 ) transverse to the channel axis (M). The air twist chamber ( 2 ) comprises a chamber length ( 29 ) in the yarn guiding direction (F) and a chamber extension ( 28 ) transverse to this length. The chamber length ( 29 ) is at least 180% of the chamber extension ( 28 ), preferably at least 200% of the chamber extension ( 28 ), and preferably the chamber length ( 29 ) is at least 1.5 mm longer than the chamber extension ( 28 ).

The invention relates to an interlacing nozzle for the production of knotted yarns, interlaced yarn, of DTY or plain yarns with knots, and a method for interlacing yarn with the features of the generic term of the independent patent claims.

Various jet devices are known from the prior art. Nozzle devices are commonly used for directing, accelerating and precisely applying fluids. By fluids are meant both gases and liquids. Nozzle devices are used, among other things, in textile machines to join, structure or treat yarns. The shape of the chamber in which the yarn treatment is carried out is decisive for achieving the desired result and the amount of fluid required for this.

In known so-called interlacing nozzles, the treatment chamber usually comprises an air twist chamber into which the fluid flow is introduced and swirled. To achieve sufficient swirling, high velocities are required. This is achieved by blowing air into the chamber at high pressure.

Interlacing nozzles are used to treat all kinds of threads, yarns, cables or similar materials. These can be made of artificial fibers (plastics such as PE, PP, etc.). They can also be made of natural fibers (cotton, wool, raffia, etc.) or mixed fibers. Herein, the term “yarn” is used to refer to all of these types of materials.

Interlacing nozzles are essentially used to interlace yarns made of man-made fibers. Interlacing has several advantages. For example, package build, payoff characteristics, process running properties or running characteristics in downstream processing are improved. Filament breaks are prevented. Pushed-up filaments or fluff can be bound in. In addition, the sizing application can be reduced or weaving without sizing can be made possible. Twisting/up-twisting can be replaced. Interlacing also makes it possible to combine different yarns with different properties or to produce fancy yarns.

From U.S. Pat. No. 5,809,761 a nozzle device is known, which comprises a splicing chamber with two lateral chamber regions. In this nozzle, the yarns do not move. It is not suitable for interlacing.

It is an object of the invention to remedy these and other disadvantages of the prior art. In particular, a nozzle device is to be provided which has a high efficiency and ensures reliable yarn treatment. In particular, the invention is intended to allow a desired knot thickness and/or knot count of a yarn to be achieved, with the lowest possible air pressure and air quantity and correspondingly low energy requirements.

These tasks are solved by an interlacing nozzle for the production of knotted yarns, interlaced yarn of DTY or plain yarns with knots and a method for interlacing yarn according to the characterizing part of the independent claims.

The interlacing nozzle according to the invention comprises a yarn channel with an air twist chamber. The air twist chamber has an injection opening for introducing air into the air twist chamber. A channel axis extends in a yarn guiding direction. The yarn channel has a channel width transverse to the channel axis.

The air twist chamber has a chamber length in a yarn guiding direction and a chamber extent transverse to said length. The chamber length is at least 180% of the chamber extension, preferably at least 200%.

Surprisingly, it has been found that by selectively choosing the shape and dimension of the chamber, the knot count and/or quality can be controlled.

Typically, as described below, the chamber length, the shape or proportions of the cross-section of an injection opening, the chamber expansion, or the angle of chamber walls relative to the wall of the yarn channel can be selectively adjusted individually or in combination to set a desired knot count and/or quality.

For example, a chamber length (relative to the chamber extension) of between 210% and 230%, in particular about 220%, leads to the formation of fewer but more stable knots. A length of between 320% and 340%, in particular about 330% leads to many but less stable nodes . . . . The chamber length is preferably at least 1.5 mm longer than the chamber extension. A further aspect of the invention therefore relates to a method for adjusting the number and/or quality of knots, in which the shape and dimension of the chamber is specifically selected for defining the number and/or quality of knots, In particular, a chamber length is selected relative to the chamber extent, wherein a shorter length is selected for forming a few but more stable knots and a greater length is selected for forming more but therefore less stable knots. In any case, the lengths are more than 180% of the chamber extension and are preferably selected as described above.

The air flow vectors (flow direction and strength of the air flow) within the air twist chamber, in conjunction with the overhang, are decisive for the number and strength of the nodes. The overfeed indicates how much more yarn length is introduced into the nozzle than comes out of the nozzle. This excess is used for knot formation. Different components of the air flow vectors lead to different effects when treating yarn in interlacing nozzles: Components of the air flow vectors, which are directed in yarn guiding direction or the opposite direction to it, influence yarn feed and yarn tension. Components of the air flow vectors which lead transversely to these directions interlace the yarn and are thus essential for knot formation. The inventors have come to the conclusion that, in order to achieve optimum treatment, the air flow in the air twist chamber should be directed in such a way that the air flow has more transverse components than components in the yarn guiding direction or in the opposite direction to the yarn guiding direction. Outside the air twist chamber, on the other hand, the air flow vectors should have more components in yarn guiding direction to ensure sufficient yarn delivery. The air flow vectors can be influenced by the geometry of the air twist chamber, the yarn channel and the injection opening.

In order to achieve both a sufficient number and strength of knots and sufficient yarn tension and guidance, high air pressures and quantities were necessary with conventional interlacing nozzles. By steering the air flow through the geometry in accordance with the invention, the proportions of the air flow vectors in the yarn guiding direction and in the transverse direction are optimized in such a way that the air quantity and air pressure can be reduced without compromising quality and thus energy can be saved.

It has been shown that a ratio of a chamber length of the air twist chamber to a chamber extension transverse to the chamber length of at least 1.8 directs the air flow within the air twist chamber over a longer area transverse to the yarn guiding direction, so that lower air pressures and air quantities are necessary to ensure sufficient interlacing of the yarn. Such an interlacing nozzle guides the air flow introduced through the injection opening in such a way that the amount of fluid introduced can be reduced by up to 20% and yet the yarn still has the required knot count and knot strength after treatment.

In particular, the chamber length can be 180%, 200%, 218%, 228%, 330% of the chamber extension, preferably at a chamber extension of 1.5 mm, 2 mm, 3 mm or 3.5 mm. Specific values may be, for example, 1.75 mm, 2.67 mm, 2.94 mm or 3.08 mm. Preferably, the chamber length is at least 35% of the total nozzle length. The total nozzle length consists of the yarn channel length and the chamber length.

The chamber extension is understood here as the maximum extension of the air twist chamber in a transverse direction transverse to the yarn guiding direction and to an air twist chamber depth.

The air twist chamber may comprise two chamber regions in direct succession, the chamber length being composed of the lengths of the chamber regions.

The air twist chamber may comprise only one chamber region, the chamber walls of which are rounded. The radius of the rounding of the chamber walls may increase in yarn guiding direction to the center of the air twist chamber and then decrease again.

However, the air twist chamber may also comprise two air twist chamber regions, the walls of which are rounded in yarn guiding direction and the rounding of the first region in yarn guiding direction has a larger radius than that of the second region. In this case, the walls of the regions preferably merge into one another without a kink.

The air twist chamber regions may have a cross-section in a plane along the channel axis of the yarn channel and in the transverse direction which is substantially teardrop-shaped, such that the chamber regions have round sections and straight sections. The straight sections are arranged to converge in the yarn guiding direction and the opposite direction, respectively.

Preferably, the injection opening is arranged in the interlacing nozzle such that the air flow enters the air twist chamber at an angle greater than or less than 90° to the channel axis. Preferably, the injection opening is arranged so that the air flow enters the air twist chamber in a region of smaller extent than the chamber extent.

Preferably, the chamber extent is 15-45% of the channel width, preferably 15% and 35%, and preferably the chamber extent is at most 5 mm, preferably at most 3 mm wider than the channel width. When the chamber length is 330% of the chamber extent to form many nodes, the chamber extent is less. Typically, it is adjacent to 15% relative to the channel width. To create fewer but more stable nodes, a larger chamber extent is selected, e.g., 35% relative to the channel width.

This improves the air flow from the chamber into the yarn channel. The chamber expansion can preferably be between 1.75 mm and 17 mm.

Preferably, the chamber length is at most 350% of the channel width and is in particular at most 30 mm, preferably at most 20 mm, greater than the channel width.

Preferably, the air twist chamber has chamber walls which have at least one wall segment rounded in yarn guiding direction, in particular with a radius between 0.3 mm and 6 mm, preferably between 0.5 mm and 2 mm.

Preferably, the chamber is convexly rounded. Preferably, the chamber walls additionally comprise straight wall segments.

This allows the air to be easily guided in a specific direction.

Preferably, the chamber wall widens as viewed in yarn guiding direction starting from a channel wall. In particular, the chamber wall may widen at an angle of no more than 5° with respect to the yarn guiding direction and the channel wall.

Preferably, a first chamber region is arranged first in yarn guiding direction and a second chamber region immediately follows the first chamber region in yarn guiding direction. At the transition from the first chamber region to the second chamber region, the chamber has a constriction so that the chamber expansion in the first and second chamber regions is greater than the chamber expansion at the transition.

This allows the air flow to be separated. Due to the certain separation of the air mass, the amount of air per chamber region can be controlled in addition to the injection angle.

The air twist chamber may also include more than two chamber regions, each separated by constrictions. The air twist chamber may include other structures to direct the air flow, such as surface structures, ribs, edges, constrictions, or widenings. The air twist chamber may include coatings for swirling air.

The first chamber region may have a first chamber depth transverse to the chamber length and the chamber extent, and the second chamber region may have a second chamber depth transverse to the chamber length and the chamber extent, wherein the chamber depths may be different.

According to another aspect of the invention, the interlacing nozzle comprises a yarn channel having an air twist chamber. The air twist chamber has an injection opening for introducing air into the air twist chamber. A channel axis extends in a yarn guiding direction. According to the invention, the injection opening has a cross-section with at least one round section and at least one air guiding section, wherein the air guiding section is straight or has a radius of curvature that is at least 10 times larger than the radius of curvature of the round section.

The cross-sectional geometry of the injection opening has a direct influence on the quality of the turbulence and on the vectors of the flow direction.

Preferably, the air duct section(s) is not parallel to the channel axis. In an interlacing nozzle, the air flows in the transverse direction are decisive for the interlacing of the yarn. If the air is directed more in the transverse direction, the yarn will be more interlaced and more and stronger knots will be formed.

Preferably, the injection opening comprises, in cross-section, exactly four straight air conduit sections arranged in a substantially diamond shape and preferably interconnected by round corners forming the round sections. Preferably, a first line of symmetry of the diamond shape is arranged parallel to and preferably coinciding with the channel axis, so that a first corner of the diamond shape points in the yarn guiding direction and a second corner points in the opposite direction to the yarn guiding direction, and a third and a fourth corner point away in a common plane perpendicular to the first line of symmetry.

Thus, the air flow is easily directed already at the blowing-in stage The cross-sectional shape may alternatively be triangular or polygonal, with the corners being rounded in each case. Preferably, the shape comprises an even number of rounded corners, the cross-sectional shape being arranged in the air twist chamber such that the corners lead in both the yarn guiding direction and the opposite direction thereto.

The cross-sectional shape may also be trapezoidal or kite-shaped.

It has been shown that the number of knots and the stability of the knots can be influenced by the choice of the cross-sectional shape. A diamond shape injection opening results in fewer but more stable knots. A kite-shaped injection opening leads to more but less stable knots.

Preferably, the corners of the diamond shape are rounded. Preferably, the injection opening comprises a cross-section with an opening length in the yarn guiding direction and an opening width transverse to the opening length. The opening length and the opening width are different, and in particular a ratio between the opening length and the opening width is between 1.0 and 1.5. A smaller ratio, typically 1.0, is used to generate many nodes.

Thus, the rhombus comprises angles between the sides which are greater than or less than 90°. Preferably, the curves of the obtuse corners comprise a different radius than the curves of the acute angle corners.

Alternatively, the injection opening can be at least approximately oval in cross-section.

The specific selection of opening width and length allows the air volume to be steered in a particular direction: if the opening length is greater than the opening width, the angle at which the air flows into the chamber at the greatest velocity changes. The air flow can thus be directed.

Preferably, the opening length is smaller than the opening width, and preferably the first and second corners of the diamond shape are rounded with a larger radius than the third and fourth corners.

Alternatively, the opening width may be less than the opening length, with preferably the third and fourth corners of the diamond shape being rounded to a greater radius than the first and second corners.

This specific choice of opening allows precise alignment of air flow and air volume, and thus air velocity, depending on the yarns to be treated.

Another aspect of the invention relates to an interlacing nozzle having a yarn channel with an air twist chamber, which includes an injection opening for introducing air into the air twist chamber. In particular, the interlacing nozzle is an interlacing nozzle as previously described. A channel axis extends in a yarn guiding direction. The yarn channel has a channel width transverse to the channel axis. The air twist chamber has a chamber length in the yarn guiding direction and a chamber extension transverse to this length. The air twist chamber and/or the injection opening are so formed and arranged in the yarn channel that air introduced through the injection opening is guided in a vector which has more transverse components transverse to the channel axis inside the air twist chamber than axial components along the channel axis and more axial components than transverse components outside the air twist chamber.

In an interlacing nozzle, the air flow leading in the transverse direction to the channel axis results in greater interlacing of the yarn and is thus decisive for knot formation in the yarn.

The air flow in axial direction conveys the yarn in yarn guiding direction and thus leads to stronger yarn tension. As the air flow in the air twist chamber is more transverse than axial, more knots are created in the yarn. If the air is also guided more in the axial direction outside the air twist chamber, sufficient yarn tension is maintained to ensure a stable process. If the yarn tension is too low, the yarn flutters so much in front of the nozzle that it can break. Here, transverse components always include both radial and tangential components, since the radial components are decisive for the number of knots and the tangential components for the yarn tension.

The air twist chamber can be designed in such a way that the air is swirled over a range of at least 40% of the total nozzle length. The total jet length includes the length of the yarn channel and the chamber length of the air twist chamber.

Preferably, the transverse components include more radial components than tangential components.

The air is thus twisted more, which also twists the yarn more, creating stronger and more knots.

Alternatively, the transverse components have more tangential components than radial components.

This causes the yarn to be guided out of the die more, creating more yarn tension.

Further, the tasks are solved by a method for interlacing yarn. The yarn is guided along a yarn channel axis of a yarn channel of an interlacing nozzle. Air is introduced into an air twist chamber and guided in a vector within the air twist chamber. The vector inside the air twist chamber comprises more transverse components transverse to the channel axis than axial components along the channel axis, and outside the air twist chamber more axial components than transverse components.

This provides a simple way to ensure that the yarn achieves a high number of strong knots at low air volumes or pressures.

The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawings will be provided by the Office upon request and payment of the necessary fee.

The invention is described in more detail in the figures. The figures show:

FIG. 1 : A top view of a first embodiment of an interlacing nozzle according to the invention for producing a few stable knots.

FIG. 2 : Detail D from FIG. 1

FIG. 3 : An injection opening from FIG. 1

FIG. 4 : A top view of a second embodiment of an interlacing nozzle according to the invention

FIG. 5 a -d: Representations of the velocities of the air flow in an injection opening with a circular cross-section and scale of the velocities

FIG. 6 a -d: Representations of the velocities of the air flow in an injection opening with a diamond shape cross-section and scale of velocities

FIG. 7 a -d: Representations of the velocities of the air flow in a prior art interlacing nozzle with an air twist chamber with smaller chamber length than chamber extension and scale of velocities.

FIG. 8 a -d: Representations of the velocities of the air flow in an interlacing nozzle with an air twist chamber with a larger chamber length than chamber extension and scale of the velocities.

FIG. 9 : A side-by-side illustration of air flow velocities of various interlacing nozzle designs

FIG. 10 : A cross-section of an interlacing nozzle along the yarn feed direction, and

FIGS. 11 a and 11 b: examples of interlaced yarns

FIG. 12A top view of a further embodiment of an interlacing nozzle according to the invention for producing more but less stable knots

FIG. 13 : An injection opening as shown in FIG. 12 and

FIGS. 14 a and 14 b a comparison of the number of knots and knot stability of yarn treated with nozzles according to the invention and with nozzles according to the state of the art.

FIG. 1 shows a top view of a first embodiment of an interlacing nozzle 100 according to the invention. The shape, size and geometry of the nozzle is designed to produce few but stable knots. The interlacing nozzle 100 comprises a nozzle plate 10 having a yarn channel 1 with two channel sections 1 a and 1 b and an air twist chamber 2 between the sections 1 a and 1 b. A yarn guiding direction F runs along central axes Ma and Mb of the channel sections 1 a and 1 b. The air twist chamber 2 comprises two chamber regions 2 a and 2 b. At the transition between the first chamber region 2 a and the second chamber region 2 b, an injection opening 4 is arranged through which an air flow is injected into the air twist chamber 2.

Along the yarn guiding direction F, the first channel section 1 a is arranged first, followed by the first chamber region 2 a, the second chamber region 2 b and then the second channel section 1 b.

An inlet section 3 a is arranged at the inlet of the first channel section 1 a and an outlet section 3 b is arranged at the outlet of the second channel section 1 b. The channel section 1 a is shorter than the channel section 1 b. Both channel sections have an extension 21 in the direction of the drawing plane of 1.7 mm. The nozzle plate 10 has a substantially mirror symmetrical configuration with respect to a plane through the center axes Ma and Mb and perpendicular to a plate surface.

The nozzle plate 10 includes a base surface 13, the base surface 13 having an outline comprising substantially two straight sides 15 a and 15 b arranged opposite each other and two rounded sides 16 a and 16 b also arranged opposite each other. The straight sides each have a substantially trapezoidal indentation 14 a and 14 b, the axes of symmetry of which lie on the central axes Ma and Mb. On each of the rounded sides, a protrusion 12 a and 12 b is arranged for mounting the nozzle on the holder. The protrusions 12 a and 12 b have substantially the same radius as the rounded sides 16 a and 16 b. However, the protrusions 12 a and 12 b are shorter than these sides.

The nozzle plate 10 further includes two circular openings 11 a and 11 b extending through the nozzle plate 10.

The air twist chamber 2 has a chamber length 29 of 4.69 mm in the yarn guiding direction F and a chamber extension 28 of 2.32 mm. The chamber extension 28 is to be understood as the largest extension of the air twist chamber 2 transverse to the chamber length 29 in the plate plane. This chamber expansion 28 and this chamber length 29 result in a length to expansion ratio of 2.02.

The nozzle plate 10 is connected to a cover plate so that the channel sections 1 a and 1 b and the air twist chamber 2 are closed. One or more yarns are introduced into and passed through the air twist chamber 2 while compressed air is applied to the yarn or yarns through the injection opening 4. As a result, knots are created in the yarn or yarns

Since the air twist chamber 2 is longer relative to the expansion, on the one hand the air is guided more in a transverse direction than in shorter chambers, and in addition the air is guided over a longer area in this transverse direction.

Air flow vector components transverse to the yarn guiding direction are responsible for the interlacing and thus for the knot number and strength. If the yarn is now interlaced more and over a longer area, more and tighter knots are formed.

FIG. 2 shows detail D from FIG. 1 , showing treatment chamber 2 with two chamber regions 2 a and 2 b. The chamber region 2 a has a first chamber width 22 transverse to the center axis Ma and the second chamber region 2 b has a second chamber width 23 transverse to the center axis Mb. A constriction 5 is arranged between the chamber regions 2 a and 2 b. That is, the chamber width 22 of the first chamber region 2 a and the chamber width 23 of the second chamber region 2 b are greater than the chamber width 51 between the chamber regions 2 a and 2 b. The chamber width 23 of the second chamber region 2 b is equal to or greater (preferably about 5%) than the chamber width 22 of the first chamber region 2 a. The chamber length here is about 200% of the chamber extent. The chamber regions 2 a and 2 b have a teardrop-shaped cross-section in the plate plane with sections with a rounding and straight sections converging in yarn guiding direction.

This constriction 5 causes the air flow to be separated, creating two areas in which the air and thus the yarn are swirled differently.

The first chamber region 2 a has a first region length 24 parallel to the central axes Ma and Mb, which is equal to or greater than the second region length 25 of the second chamber region 2 b parallel to the central axes Ma and Mb. The chamber length 29 of the air twist chamber 2 consists of the first region length 24 and the second region length 25 and is 5.1 mm.

The chamber walls of the chamber regions 2 a and 2 b each lead away from the walls of the yarn channel at an angle. The chamber walls of the first chamber region 2 a have an angle P of about 18° to 20° (specifically 19°) with respect to the walls of the yarn channel, and the chamber walls of the second chamber region 2 b have an angle S of also 18° to 20°. A smaller angle (see also FIGS. 12 and 13 below) is used to produce many knots, and a larger angle is used to produce fewer but more stable knots. The area lengths 24 and 25 are determined by the chamber expansion (i.e., the width of the air twist chamber) and the angle. The widths of the air twist chambers and/or the angles can be the same or different.

However, other dimensions and geometries are also conceivable. The geometries described above can also be used for nozzle lengths of up to 45 mm with channel widths of up to 12 mm. The radii, e.g. in the yarn channel base, can then be adapted accordingly.

FIG. 3 shows the injection opening 4 from the embodiment example, from FIG. 1 . The chamber regions 2 a and 2 b of the air twist chamber 2 (cf. FIG. 1 ) are arranged directly one after the other, whereby the air twist chamber 2 (cf. FIG. 1 ) has a constriction 5 in the width at the transition between the chamber regions 2 a and 2 b. The injection opening 4 is arranged at the transition between the chamber regions 2 a and 2 b. A larger part of the cross-section of the injection opening 4 leads into the first chamber region 2 a.

The injection opening 4 has a cross-sectional shape which is essentially a parallelogram with rounded corners 41-44. The rounded corners 41-44 are rounding sections. The sides of the parallelogram shape are air guiding sections 45, which serve to guide air in a particular direction. The first corner 41 points in yarn guiding direction F, and the second corner 42 points in the opposite direction to the yarn guiding device, so that the symmetry line 40 of the parallelogram shape is arranged along the center axes Ma and Mb. The first corner 41 and the second corner 42 are both rounded with a radius of 0.2 mm-2.5 mm. The third corner 43 and the fourth corner 44 are both in a plane perpendicular to the central axes Ma and Mb and are both rounded with a radius of 0.3 mm-3 mm. The angle between the straight sections is about 50° for the acute angle and about 130° for the obtuse angle. The injection opening has a width of typically 1 mm-10 mm, preferably about 1.32 mm, and a length of 0.8 mm-7 mm, preferably about 0.99 mm, and thus a width to length ratio of about 1.33:1.

If the injection opening has a parallelogram or diamond shape, as shown, the air is guided increasingly in a transverse direction to the yarn guiding direction, the transverse direction having components in both tangential and radial directions. The corners 41 and 42, which lie on the line of symmetry in the yarn guiding direction, are obtuse and the other corners 43 and 44 are acute. The angle of the corners has an influence on the orientation of the air flow, so that depending on whether the flow is to comprise more tangential or radial components, the angle can be adjusted.

FIG. 4 shows a top view of a second embodiment of an interlacing nozzle 100 according to the invention. The interlacing nozzle 100 of this embodiment has substantially the same nozzle plate 110 as the nozzle plate of the first embodiment. Therefore, only the differences from the first embodiment will be discussed below.

The air twist chamber 102 of this embodiment has two chamber regions, wherein the chamber walls 127 a of the first chamber region arranged in the yarn guiding direction F has a rounding in the yarn guiding direction with a radius which is larger than the radius of the rounding in the yarn guiding direction F of the wall portions 127 b of the second chamber region. The radius of the rounding of the first wall portion 127 a may vary. Typically, it is about 25 mm. The radius of the roundness of the second wall section 127 b may also vary and be about 15 mm.

In the embodiment example shown here, the chamber length 129 of the air twist chamber 102 is 6.85 mm, and the chamber extension 128 is 3 mm. The extension 121 of the yarn channel 101 is 2.4 mm.

The injection opening 104 comprises substantially the same cross-sectional shape of a parallelogram as shown in FIG. 3 , with rounded corners.

The injection opening 104 is arranged so that the air flow enters the air twist chamber 102 at an angle of less than 90°.

FIG. 5 a shows a nozzle with an injection opening having a circular cross-section, as used in prior art interlacing nozzles. To illustrate the influence of the cross-sectional shape on the air flow, a simulation was carried out. The simulation in FIGS. 5 b-5 d (and also 6 b-6 d) was based on an interlacing nozzle with a yarn channel without an air twist chamber.

Such an injection opening, known per se, can also be arranged in an air twist chamber 2 of an interlacing nozzle according to the invention as shown in FIG. 1 or 4 .

FIG. 5 b shows a scale of the flow velocities shown in FIGS. 5 c and 5 d.

FIG. 5 c shows the velocities of the air flows in the top view of the nozzle of FIG. 5 a . It can be seen that the flow of air with the highest velocity 70 in area 150 mostly flows in the yarn guiding direction F or opposite direction. Areas 151 with relatively high velocity 71 are mainly located at the yarn channel walls and also lead in yarn guiding direction F or opposite direction. Between the yarn channel walls in region 151, however, there are regions in the center mainly with relatively low velocity 72 or low velocity 73, which lead in yarn guiding direction F or opposite direction.

FIG. 5 d shows a side view of the flow velocities of the nozzle of 5 a. The air flow is mainly directed to the center of the yarn channel in the region 152 of the injection opening, that is, there is a region 152 with high velocity 70 in the center of the yarn channel in the region of the injection opening with transverse components. In region 153, there are occasional areas of flow vectors with high velocity also in the transverse direction in the center of the yarn channel. However, the areas with high velocity here also increasingly lead along the wall opposite the entry opening in yarn guiding direction or in the opposite direction.

FIG. 6 a shows an injection opening with diamond shape cross-section without air twist chamber to show the influence of the geometry of the nozzle opening on the air flow.

FIG. 6 b shows a scale of the flow velocities.

FIG. 6 c shows a representation of the flow velocities of the nozzle in plan view. This illustration shows that an injection opening with a diamond shape cross-section has a larger area 160 with a high flow velocity 70 than in FIG. 5 c and that the flow deviates more from the yarn guiding direction F or its opposite direction. In addition, FIG. 6 c shows that a nozzle with an injection opening with a diamond shape cross-section has more areas 161 with a relatively high flow velocity 71, and this is also guided more in the center between the walls of the yarn channel than in FIG. 5 c.

FIG. 6 d shows a side view of the flow velocities of the nozzle of FIG. 6 a . FIG. 6 d also shows that a nozzle with a diamond shape injection opening has a larger area 163 with a relatively high velocity 71, which is also directed more to the center between the channel walls than in the nozzle shown in FIG. 5 d.

FIG. 7 a shows a prior art nozzle with a circular injection opening and an air twist chamber with a chamber length smaller than the chamber dimension.

FIG. 7 b shows a scale of flow velocities.

FIG. 7 c shows a top view of the flow velocities of the nozzle from FIG. 7 a . It can be seen that the flow has a few areas 170 with high velocity where the flows are in the transverse direction to the yarn guiding direction. There are areas 171 outside the chamber where the flow has a relatively high velocity 71 and is primarily in the yarn guiding direction or opposite direction.

FIG. 7 d shows a side view of the flow velocities of the nozzle of FIG. 7 a . Here, the flow is mainly guided in the transverse direction in the area 172 of the injection opening. In a small area 173 outside the chamber, the flow has a high velocity and leads in yarn guiding direction, resp. opposite direction.

FIG. 8 a shows a nozzle according to the invention with an air twist chamber having a chamber length which is 2.5 times larger than the chamber extension.

FIG. 8 b shows a scale of the flow velocities.

FIG. 8 c shows a top view of the flow velocities of the nozzle of FIG. 8 a . It can be seen that the flow has large areas in the chamber which have flows with high velocity 71 leading in transverse direction to the yarn guiding direction F and in the middle of the areas 180 in yarn guiding direction flows with high velocity 71 leading in yarn guiding direction F resp. opposite direction.

FIG. 8 d shows a side view of the flow velocities of the nozzle from FIG. 8 a . It can be seen that in larger areas 182, 183 the flow is more concentrated in the center between the walls of the yarn channel, i.e. in transverse direction to the yarn guiding direction F than shown in FIG. 7 d . The flows in area 183 near the injection opening have a high velocity 71, and in area 182 a somewhat lower velocity 73. There is therefore less air flow in yarn guiding direction F.

FIG. 9 shows a side-by-side representation of air flows from various nozzles.

Illustration 80 shows the air flow of a nozzle without an air twist chamber, as in FIG. 5 a.

FIG. 81 shows the air flow of a nozzle with an air twist chamber having a chamber length smaller than the chamber dimension, as in FIG. 7 a.

The illustration 82 shows the air flow of a nozzle according to the invention with an air twist chamber with a chamber length which is 1.6 times as large as the chamber extension.

FIG. 83 shows the air flow of a nozzle according to the invention with an air twist chamber with a chamber length which is more than twice as large as the chamber extension. In FIG. 80 , the airflow is distributed so that relatively few airflows are concentrated in the center. Lines 84 show that increasing the length of the chamber results in an increased orientation of the flow toward the center.

FIG. 10 shows in simplified form a cross-section through a nozzle plate 10 in yarn guiding direction. The yarn channel 1 has the air twist chamber 2 in the center, into which the injection opening 4 opens at an angle in the yarn guiding direction F.

FIGS. 11 a and 11 b show an example of an interlaced DTY yarn (FIG. 11 a ) and an interlaced plain yarn (FIG. 11 b ).

FIGS. 12 and 13 show a further embodiment of a nozzle according to the invention in a representation analogous to the representation of the first embodiment in FIGS. 1 and 2 . Identical reference signs designate identical elements as in FIGS. 1 and 2 and are not described again. In contrast to the embodiment in FIGS. 1 and 2 , the nozzle according to FIGS. 12 and 13 is designed to generate more and therefore less stable nodes.

The channel sections 1 a, 1 b have an extension 21 in the direction of the drawing plane of 1.7 mm.

The air twist chamber 2 has a chamber length 29 of 6.74 mm in the yarn guiding direction F and a chamber extension 28 of 2.0 mm. This chamber expansion 28 and this chamber length 29 result in a length to expansion ratio of approximately 3.37.

The chamber walls of chamber regions 2 a and 2 b each lead away from the walls of the yarn channel at an angle of about 6°. This serves to create many knots

FIG. 13 shows the injection opening 4 from the embodiment example, from FIG. 12 . A smaller part of the cross-section of the injection opening 4 leads into the first chamber region 2 a.

The injection opening 4 has a kite-shaped cross-sectional form with rounded corners and with a rounded boundary in the chamber region 2 a.

The injection opening 4 has a width B of about 1.13 mm and a length L of about 1.1 mm, and thus a width to length ratio of about 1:1.

The kite shape has an asymmetrical structure: Its length in chamber region 2 a is 0.5 mm and in chamber region 2 b 0.6 mm.

With nozzles according to the invention as shown in FIG. 1 , comparative tests were made with nozzles as known from the prior art (see, for example, FIG. 14 a from WO 2006/099763). In these tests, the operating conditions (in particular the air volume at a given blowing pressure) were adjusted so that, as far as possible, the same account number and knot stability were obtained. FIGS. 14 a and 14 b show the knot count (FIG. 14 a ) and knot stability (FIG. 14 b ) of yarns (PES POY dtex 110/78f36) respectively with a nozzle according to the invention (X45.40) and a nozzle according to the stand (P142). To achieve the almost identical knot count and knot stability, approx. 20% less air was consumed with the nozzle according to the invention. 

1-17. (canceled)
 18. An interlacing nozzle for the production of knotted yarns, interlaced yarn, DTY or plain yarns with knots, comprising a yarn channel with an air twist chamber, wherein the air twist chamber has an injection opening for introducing air into the air twist chamber, a channel axis extends in a yarn guiding direction, the yarn channel has a channel width transverse to the channel axis and the air twist chamber has a chamber length in the yarn guiding direction and a chamber extension transverse to the chamber length, the chamber extension having a chamber extension length, and wherein the chamber length is at least 180% of the chamber extension length.
 19. The interlacing nozzle according to claim 18, wherein the chamber extension length is 15%-45% of the channel width.
 20. The interlacing nozzle according to claim 18, wherein the chamber length is at most 350% of the channel width.
 21. The interlacing nozzle according to claim 18, wherein the air twist chamber comprises chamber walls which comprise at least one rounded wall segment.
 22. The interlacing nozzle according to claim 21, wherein the chamber walls comprise straight wall segments.
 23. The interlacing nozzle according to claim 18, wherein the chamber wall expands from a channel wall as viewed in the yarn guiding direction at an angle of no more than 5° with respect to the yarn guiding direction and the channel wall.
 24. The interlacing nozzle according to claim 18, wherein the air twist chamber comprises a first chamber region and a second chamber region, wherein the first chamber region is arranged first in yarn guiding direction and the second chamber region immediately follows the first chamber region in yarn guiding direction, wherein at the transition from the first chamber region to the second chamber region the chamber has a constriction so that the chamber expansion in the first and second chamber regions is greater than the chamber expansion at the transition.
 25. An interlacing nozzle for the production of knotted yarns, interlaced yarn, of DTY or plain yarns with knots comprising a yarn channel with an air twist chamber, wherein the air twist chamber has an injection opening for introducing air into the air twist chamber and wherein a channel axis extends in a yarn guiding direction, wherein the injection opening has a cross-section with at least one round section and at least one air guiding section, wherein the air guiding section is straight or has a radius of curvature which is at least 10 times larger than the radius of curvature of the round section.
 26. The interlacing nozzle according to claim 25, wherein the air guide section is arranged at an angle to the channel axis.
 27. The interlacing nozzle according to claim 25, wherein the injection opening comprises exactly four air guiding sections in cross-section, which are arranged in a substantially diamond shape, so that a first corner of the diamond shape points in yarn guiding direction and a second corner points in the opposite direction to the yarn guiding direction, and a third and a fourth corner are arranged pointing away in a common plane perpendicular to the first line of symmetry.
 28. The interlacing nozzle according to claim 27, wherein the corners of the diamond shape are rounded.
 29. The interlacing nozzle according to claim 25, wherein the injection opening comprises a cross-section with an opening length in yarn guiding direction and an opening width transverse to the opening length, wherein the opening length and the opening width are different.
 30. The interlacing nozzle according to claim 27, wherein the opening length is smaller than the opening width.
 31. The interlacing nozzle according to claim 27, wherein the opening width is smaller than the opening length.
 32. An interlacing nozzle for the production of knotted yarns, interlaced yarn, of DTY or plain yarns with knots comprising a yarn channel with an air twist chamber, wherein the air twist chamber has an injection opening for the introduction of air into the air twist chamber, a channel axis extends in a yarn guiding direction and the yarn channel has a channel width transverse to the channel axis, the air twist chamber has a chamber length in the yarn guiding direction and a chamber extension transverse to said length, wherein the air twist chamber and/or the injection opening is designed and arranged in the yarn channel in such a way that air introduced through the injection opening is guided in a vector which, inside the air twist chamber, has more transverse components transverse to the channel axis than axial components along the channel axis and, outside the air twist chamber, has more axial components than transverse components.
 33. The interlacing nozzle according to claim 32, wherein the transverse components comprise more radial components than tangential components.
 34. The interlacing nozzle of claim 32, wherein the transverse components comprise more tangential components than radial components.
 35. A method for interlacing yarn, wherein the yarn is guided along a channel axis of a yarn channel of an interlacing nozzle and the introduced air is guided inside an air twist chamber in a vector, wherein the vector inside the air twist chamber comprises more transverse components transverse to the channel axis than axial components along the channel axis and outside the air twist chamber comprises more axial components than transverse components.
 36. The interlacing nozzle according to claim 18, wherein the chamber length is at least 1.5 mm longer than the chamber extension length.
 37. The interlacing nozzle according to claim 18, wherein the chamber extension length is at most 5 mm wider than the channel width.
 38. The interlacing nozzle according to claim 21, wherein the rounded wall segment has a radius between 0.3 mm and 6 mm.
 39. The interlacing nozzle according to claim 25, wherein the interlacing nozzle comprises a yarn channel with an air twist chamber, wherein the air twist chamber has an injection opening for introducing air into the air twist chamber, a channel axis extends in a yarn guiding direction, the yarn channel has a channel width transverse to the channel axis and the air twist chamber has a chamber length in the yarn guiding direction and a chamber extension transverse to the chamber length, the chamber extension having a chamber extension length, and wherein the chamber length is at least 180% of the chamber extension length.
 40. The interlacing nozzle according to claim 32, wherein the interlacing nozzle comprises a yarn channel with an air twist chamber, wherein the air twist chamber has an injection opening for introducing air into the air twist chamber, a channel axis extends in a yarn guiding direction, the yarn channel has a channel width transverse to the channel axis and the air twist chamber has a chamber length in the yarn guiding direction and a chamber extension transverse to the chamber length, the chamber extension having a chamber extension length, and wherein the chamber length is at least 180% of the chamber extension length. 